LASEK (or laser epithelial keratomileusis) is another laser vision correction procedure for patients whose corneas are too thin for LASIK. LASEK resembles PRK in that the surgeon doesn't create a LASIK-style flap in the first step of the procedure. But instead of removing the outer layer of corneal cells (the epithelium) completely, the LASEK surgeon creates an epithelial flap and replaces it after the excimer laser treatment is completed.

LASEK offers results that are similar to those achieved by LASIK, but (like PRK) it involves more post-operative discomfort and longer healing times.


The LASEK procedure

Trephine used in LASEK surgery. Image courtesy of Rhein Medical, Inc.

The steps in LASEK surgery are:

1. Anesthetic eye drops are applied to the eye to prevent pain during the surgery.
2. The outer layer of corneal cells (the epithelium) is scribed with a hand-held surgical tool called a trephine. The trephine has a cylinder-shaped blade that forms the outline of the flap. A gap in the arc of the blade allows for the hinge of the flap.
3. A dilute alcohol solution is applied for the eye for about 30 seconds, and then is sponged off. (The alcohol solution loosens and helps "float" the epithelium.)
4. The epithelium is gently lifted from the eye and folded back.
5. An excimer laser is used to reshape the underlying cornea (called the stroma).
6. The thin epithelial flap is put back in its original position. To keep the epithelium securely in place, a bandage contact lens is applied.
7. Three or four days later (after the epithelium has had a chance to securely reattach to the eye), the bandage contact lens is removed.

Considerations after LASEK surgery

• There is more post-operative discomfort after LASEK compared to LASIK (but perhaps less than after PRK). This discomfort may last for a week or more.
• It can take a week or more to recover good vision. Glare, blurred vision and sensitivity to light are common for several days or longer after the procedure.
• Due to the potential for blurred vision for a time after LASEK, some surgeons perform LASEK one eye at a time (performing LASEK on the other eye later, after vision in the first eye is acceptably clear).
• You may be required to use medicated eye drops for up to 6 months after LASEK to prevent or reduce corneal haze or scarring.

Risks and complications of LASEK

As with LASIK and other types of refractive surgery, there are risks and possible complications associated with LASEK. Potential complications are similar to those of LASIK, and include:

• Dry eyes.
• Vision problems, such as poor night vision, glare, halos and haze.
• Incomplete or inaccurate vision correction.
• Infection following surgery.

There may be a slightly greater risk of eye infection, scarring, glare and unpredictable healing of the cornea after LASEK compared to LASIK. But serious complications following LASEK are rare.


Other information about LASEK

Since there is only a very thin epithelial flap in LASEK surgery, it can be used to treat corneas that are too thin for LASIK.

Though the visual outcomes of LASEK and LASIK are quite similar 6 months after surgery, LASEK (like PRK) is not as popular as LASIK because of its associated post-operative discomfort, short-term blurred vision and longer healing time. By comparison, LASIK patients experience little or no discomfort and frequently see quite well the following day.

LASEK is typically used to correct up to -7.00 diopters (D) of nearsightedness and up to +6.00 D of farsightedness, with or without astigmatism. During LASEK, the excimer laser can be programmed to deliver a standard laser treatment (ablation) or a wavefront-guided custom ablation, just like that used for wavefront-guided LASIK.

The cost of LASEK is comparable to the cost of LASIK surgery.